Opinion: What I’ve learned from hanging out with obesity scientists
How much of the obesity epidemic is due to unhealthy food, and how much to unhealthy chemicals? Ultimately, we need to be rid of both.
What goes through your mind when you hear someone say they want to lose weight? “Eat less; exercise more,” right?
That’s also our collective assumption about the global obesity epidemic — humanity is eating too much and moving around too little.
If you aren’t familiar with this epidemic, let’s get you up to speed. It is roughly 50 years and ongoing, global in scope, and affects people of all ages and animals. If unchecked is likely catastrophic. Roughly 2 billion people are overweight. And even if being overweight is not a synonym of being ill, it’s a fact that obesity is often implicated in nearly all of the other health conditions that plague us. Most of humanity lives in nations where being overweight kills more people than being underweight.
That was the first challenge of my understanding: obesity is an urgent problem, rather than a sign of progress that global hunger is being solved.
As you’ve undoubtedly experienced, there is a great deal of noise on the issue, and deepening our understanding initially appeared daunting. Eventually it sorted out nicely into three theories of the causes of obesity and a path forward through their integration.
The obesity epidemic is born
The epidemic began at the same point in history that the U.S. government and nutrition professionals began promoting diets high in carbs and low in fats. Highly-processed foods exploded in availability and popularity. Inexpensive at the cash register, they are troublesome for our blood sugar levels and digestive system. They are stripped of fiber and natural nutrients, designed to create addictive-like responses (“Betcha can’t eat just one!”). They also contain a range of unnatural chemicals — some intentionally added, and others as residue.
The popularity of processed foods brought a corresponding increase in a range of deadly and debilitating chronic conditions, such as diabetes and heart disease. Anywhere on the globe processed foods were introduced, these diseases increased; sometimes in places where they’d been rare or nonexistent.
Our approach to relieving the symptoms is generating hundreds of billions of dollars in economic activity through multiple industries that provide our food and then sell us methods and medicine to lose weight. I’ve named this ‘The Weight Loss Industrial Complex.’ If obesity ended tomorrow, I hazard that the global economy would be threatened, like the housing bubble of 2008.
The most entrenched theory of obesity is known as “calories in, calories out”, or CICO.
Credit: Jaco Pretorius/Unsplash
The most entrenched theory of obesity is known as “calories in, calories out”, or CICO. It is simple math — eat more than you burn, you add fat, and vice-versa. It doesn’t matter what you eat, only calories count. Scientists call this the “energy balance” model.
CICO thinking frames obesity as a choice made by the individual, and by extension a question of character and personal discipline. It has colonized our thinking and remains the “go to” starting point for how we think and act on dieting. However, the math is now known to be wildly misleading. The burning and storage processes are complex and influenced by many factors. Decisions about food intake and exercise are experienced differently by individuals.
Our collective, global caloric intake and activity levels can’t explain the rise in obesity during the 50 year global epidemic. We haven’t eaten enough and exercised so little as to explain our collective weight gain. A person with the same calorie intake and exercise is heavier today than they were in the 1980s.
Let that sink in. CICO is deeply socialized into us on an individual and cultural level. I’ve been aware of its inadequacy for months and am still coming to terms with it.
Low carb diets
The shortcomings of CICO gave rise to a second well-known obesity theory, introduced to us through diets commonly known as “low carb.” Scientists call it the carbohydrate-insulin theory. Rather than simple addition and subtraction of calories, it focuses on carb content, and how our body generates and stores fat in response to different ratios of carbs, fats and proteins. The science focuses around how carbs stimulate insulin production and the creation of new fat cells.
This theory provides an alternative to the tragic dietary recommendations from the 1960’s, and has led to many variations of related diets. They claim to turn human metabolism into “a fat-burning engine.” Many individuals have had success losing weight through these diets, but with the typical low rates of maintenance that plagues most, if not all, diet methods.
Obesogens include chemicals we absorb when eating: ingredients such as fructose, sucralose and MSG; those released from packaging such as bisphenol-A (BPA) and phthalates; and pesticide and herbicide residues.
Neither theory can explain why other species are also gaining weight, both in controlled laboratory conditions and in the wild. They can’t explain why babies and toddlers are developing obesity and related diseases, or why a propensity to obesity starts in the womb. They can’t explain people being “programmed” for obesity during childhood. They don’t include the links between obesity and stress, the nutritional quality of food or chemical exposures.
This brings us to a third theory, the obesogen hypothesis. It recognizes obesity as rooted in a disruption of our metabolism at the chemical and cellular level by a variety of substances — “obesogens.”
Obesogens include chemicals we absorb when eating: ingredients such as fructose, sucralose and MSG; those released from packaging such as bisphenol-A (BPA) and phthalates; and pesticide and herbicide residues. We also absorb some of them through breathing the dust in our homes and contact with our skin.
They create signals in our bodies to eat more and spend less energy, which increases fat storage. This internal misinformation leads to weight gain. You might think of it as an evil, complex social media campaign inside your body from troublemaking outsiders.
From research, we know that people exposed to these chemicals during key developmental periods are primed for weight gain later in life. Scientists discovered that when animals are exposed to BPA in the womb, they get fat later in life. This has been replicated with other chemicals.
We also know that exposures in animals as far back as four generations can affect metabolism. So yes, you can point the finger at your grandparents, not because they nagged you to eat more, but because of what they were exposed to. Or their parents. And yes, your drinking water may make you fat, if it is laced with chemicals from a tainted well, residential water supply or plastic bottle.
What we know now about obesity
After 50 years there’s still no agreement among scientists about what causes obesity. We do know that each of these three theories are valuable, especially when integrated.
Obesogen chemicals also entered our lives en masse about the time the obesity epidemic began. How much of the epidemic is due to the switch to an excess of poor quality carbs, and how much to these chemicals? Nobody knows yet. Ultimately, we need to be rid of both.
As individuals, what we can do isn’t dramatic, novel or complex: healthy diet, exercise, reduce chemical exposures where we can, reduce stress, sleep well and more. The diet part has been around forever: eat fresh and whole foods, high fiber, organic when you can. Avoid added sugar, especially fructose, and artificial sweeteners.
However, solutions aren’t one-size-fits-all. Each individual’s disease state is unique and should be treated that way. The list above is a menu; not a prescription. My exposures, and those of my ancestors, are different from yours. How my body reacts to them is different from yours. And of course, our life circumstances are different. In other words, weight loss methods that work for you probably don't work for me in the same way.
Underfunded and marginalized communities typically have a hard time accessing nutrient-rich foods, and are exposed to more chemicals, at least in part explaining their higher disease rates. Obesity is a social justice issue. Unsurprisingly, the medical and social standards for obesity are largely based on the genetics and cultures of Europeans, so that needs to be cleaned up.
We need to drastically alter our relationship to nutrient-poor foods and get obesogenic chemicals out of our lives. The resistance is high: hundreds of billions of dollars are in play in the food, chemical, health care, pharmaceutical and agricultural sectors. Prevention to avoid the disease and all its required care has never been so important.
Thanks to those scientists for their patience and generosity as I asked many naive questions, often repeatedly.